Looks like you and a bunch of other people ended up waiting for their credits, and posted all at the same time, so today's a busy day. As such, I'll jump right in without pleasantries.

Starting with your organic intersections, these are mostly well done. You're definitely demonstrating a great sense of volume and solidity to your forms, though there are a few - like the top left of the first page, and the top right of the second page - where they ended up getting a little limp and wobbly, which undermined their sense of solidity somewhat. The rest were pretty good, but definitely remember to give the sausage forms the impression of being solid enough to feel like filled water balloons - they'll have the surface tension to hold their forms somewhat, but will still sag and slump as a whole.

Moving onto your animal constructions, I think it's clear that you did learn quite a bit over the course of the whole lesson. That is to say, you started a bit weak. Even though you clearly learned from your mistakes, I am still going to touch on certain issues from the earlier drawings just because they're good opportunities to talk about common mistakes that are very important to point out.

Take a look at this.

The main issue I wanted to point out was how along the back, you had gaps between your additional forms that you just stretched a flat, 2D shape across. Everything we add to our constructions must be a solid, 3D form, and we must define how it relates to the existing structure in order to continue to maintain the illusion that the result is three dimensional.

Additionally, your paws were definitely coming out as flat shapes - if you look at my little example in the bottom right, you can see how you can craft a silhouette that gives the impression that it has a front/side/top plane, making it appear 3D despite just being a shape on a page.

As you progressed through your drawings, you did start to demonstrate a better understanding of the relationships between your forms - for example, this bird's body has a lot of forms with clearly established relationships with one another, and so the result is something you feel you can reach out and pick up with your hands. The head ended up with a lot of skipped steps however - the eye socket was much too small, and you kept the different components floating apart from one another, rather than creating a sort of "3D puzzle" where all the pieces interlock. This kind of interlocking is important, and will help sell the illusion of form both with head construction as well as when adding additional forms to the body.

One last point about the bird - the crest has two main issues. First off, you left one end of each feather open, leaving it no grounding or relationship with other 3D forms, so we cannot really grasp how they exist in 3D space. As such, they end up appearing flat. Secondly, don't fill things in with black just because you see them as having a black local colour. We don't capture any other colours in our drawings, so black is no different. Instead, we reserve black for filling in our cast shadow shapes.

Skipping on down, I am starting to see a tendency to put down your underlying construction more faintly, then coming back over it all with a darker, richer, more confident line. This is incorrect - you should not be treating your initial masses any differently from the "final" linework. Those initial masses are as much a part of the final drawing as everything else, and if there are cases where those initial lines accurately capture an aspect of the full drawing - like if part of the ribcage mass captures the basic smooth edge of an animal's back, then you would not go on to redraw that edge. There would be no need to replace it, because it would already be there. So don't get in the habit of feeling the need to replace linework and separate things into an underdrawing and a "cleanup pass".

I am actually very happy with this antelope drawing. It actually does continue to show some of that first issue I pointed out along your wolf's back (stretching flat shapes across forms rather than building everything out of distinct solid masses), but as a whole it's still very well done and establishes the illusion of a solid, three dimensonal object. You also did a great job with its horns. The fur texture here is also much better than when you started - it's not as obnoxious and spiky, and instead feels more like a gentle reminder that the animal has fur, rather than a constant shriek.

For future reference, this is a tortoise. To be fair, all tortoises are in fact turtles, but colloquially, they're generally treated as being different things. Turtles are the swimmy ones. That said, while the drawing does skip some steps, I feel it captures the illusion of 3D form quite well all the same.

Now, I think you are ultimately doing a good job and I think you've learned a lot, but given that you've got one really good success and a whole lot of weaker drawings, I want to ensure that you're able to continue applying what you've learned. As such, there will be a few additional pages in your future. I do however expect that they'll come out fine.

Before that, be sure to take a look at the new puma demo I did. While it does not come out to be a rather pretty drawing, it does do a good job of demonstrating just how far you can push those additional masses, and how they can interlock one another. It also goes over head construction again, and how the eyesockets tend to be quite big and how it all fits together.